Valve lock



J. F MARTIN VALVE LOCK Nev. 8, 1938.

Filed May 2, 1938 INVENTOR JULIAN F. MARTIN ATTORNEY Patented Nov. 8, 1938 UNITED? as 2 Claims.

This invention relates to valve locks and particularly to looks for valves of the plug cock type.

An object of this invention is to provide a simple form of lock for plug cocks which cannot 5 be opened by unauthorized persons without detection of their tampering therewith, and which may be easily unlocked and opened by authorized persons.

Another object is to provide a lock mechanism 10 for plug cocks, which mechanism is of simple and relatively cheap construction, but which is efiective for the purposes for which it is designed.

Other objects and advantages of this invention will become apparent from the following de- 15 scription and the accompanying drawing which illustrates one form of the new invention.

In the drawing:

Fig. 1 illustrates a side view of the valve and locking means.

20 Fig. 2 is a top view of the device shown in Fig.

1, and

Fig. 3 is a View of the valve plug.

Referring to the drawing, a valve casing I of a conventional plug cock is fitted with the usual 25 conical plug 2 having asquare or angular turning key 3 extending from its upper end above the casing l, andhaving a threaded reduced portion 4 at its lower end to accommodate a nut 5 and washer 6 which serve, in the well known manner,

39 to secure the plug in the casing. Key 3 is provided with a bifurcating slot 1 which extends transversely through the central portion of the key and in a direction which is parallel to that of a port 8, which extends through the plug 2.

35 Slot 1 is of substantial width and its depth is preferably substantially equal to the height of key 3 above the body of plug 2. Registering openings 9--9 extend through key 3 at an angle, preferably a right angle, to slot 1 and are posi- 40 tioned in the upper portion of key 3, and are thus spaced above the bottom of slot 1. In the form of the device shown in the drawing, it will be noted that two pairs of openings 9-9 are provided in case it is desired to use more than one 45 seal member, as will be more fully described hereinafter.

A look bar [0, preferably in the form of a fiat elongated steel strip of sufiicient thickness to render the same resistant tobending, and having 50 a width only slightly less than that of slot 1 so that it may be readily received therein but without suificient clearances to permit turning of the plug when the lock bar is in place, is connected at one end to the upper rim of valve 55 casing I by means of a hinge II. The lock bar I is thus permanently attached to the valve casing and constrained by hinge l l to rotate vertically relative to the valve casing. By rotation about hinge II, the free end of lock bar Ill may be caused to enter, or be removed from, slot 1 When the plug 2 is turned in the closed position, that is, when slot 1 and port 8 are at right angles to the passageways through the valve casing. The position of lock bar II] when the valve is to be opened is shown in dotted outline in Fig. 1. 10 When lock bar I0 is in place in slot 1, it will be below the level of openings 9-9 through which a sealing strip l2 of more or less conventional form and constructed preferably of frangible metal or the like, is passed, the ends of the sealing strip I2 then being locked together in the usual manner, so that it cannot be removed from the key without being broken.

With the device as described, the valve is locked when the valve plug 2 is in the closed position, and lock bar I0 is in place in slot 1, and a sealing strip I2 is looped through openings 99. When it is desired to unlock and open the valve, it is only necessary to apply an upward pull to the free end of lock bar l0, which movement will quickly and easily break the sealing strip and leave the plug 2 free for turning to the open position, by means of a wrench bar, not shown, which may be inserted in slot 1, or by any other suitable means.

The form and method of attachment of lock bar I!) will positively prevent turning of plug 2, when the bar is in the locking position, and since the bar may be raised from the slot 1 only by breaking sealing strip I 2, tampering with the valve by unauthorized persons may be readily detected.

The lever action of bar I!) is highly effective for breaking the sealing strip and very advantageous in that no special tool need be carried. for this, purpose by the persons authorized to open the valve, and the inconvenience of breaking the seal by twisting and bending by hand, particularly in cold weather, is avoided. Furthermore, whenthe valve has been been opened, the lock bar, by virtue of its permanent attachment to the valve casing, is always available for relocking the valve and cannot be lost or misplaced.

It will be evident from the foregoing that the Valve lock of this invention consists of a very few simple and inexpensive parts which are easily accessible to the operator for quick and easy unlocking and locking of the valve.

What I claim and desire to secure by Letters Patent is:

1. A look for plug cocks comprising in combination, a valve casing, a valve plug rotatable in the casing, a turning key extending from the upper end of said plug, a bifurcating slot extending transversely through said key, an opening extending through said key at an angle to said slot, an elongated lock bar attached by a hinge at one end to said valve casing, the free end of said lock bar being constrained to rotate vertically about said hinge and to enter said slot When said valve plug is in the closed position, and a frangible seal member extending through said opening in the key and spanning said slot,

said seal member being automatically broken by vertical movement of the free end of said lock bar out of said slot.

2. A lock bar for plug cocks comprising in combination, a valve casing, a valve plug rotatable in said casing, a port extending transversely through said valve plug, an angular turning key extending from the upper end of said valve plug, a bifurcating slot extending through said key parallel to said port, an opening extending through the upper portion of said key and at right angles to said slot, an elongated lock bar attached at one end by a hinge to said casing, the free end of said lock bar being constrained to rotate vertically about said hinge and to enter said slot When said valve plug is in the closed position, and a frangible seal member extending through said opening in the key and spanning said slot, said seal member being automatically broken by the vertical movement of the free end of the lock bar out of said slot.

JULIAN F. MARTIN. 

